1. Field of the Invention
The present invention relates to an attachment element having at least one engagement member insertable in a mounting opening of a hollow body in its first position and engaging holding projections provided on the hollow body in its second position, at least one stop for engaging outer end sides of rims of longitudinal sides of the hollow body which limit the mounting opening, and at least one fastening element which displaces, upon being actuated, the at least one engagement member from its first position to its second position.
2. Description of the Prior Art
Attachment elements of the type described above are used for securing objects, e.g., on a C-shaped mounting rail that can, e.g., be secured on a constructional component. The attachment element is inserted in a mounting opening and, e.g., is pivoted by 90° so that the engagement member of the attachment element engages holding projections provided on the mounting rail. With this preliminary attachment, the attachment element can be displaced in the longitudinal direction of the mounting rail for adjusting the attachment element. In order to finally secure the attachment element on the mounting rail, the engagement member is secured to a stop, e.g., with a threaded rod so that it is clamped to the projections. This type of attachment element is suitable, e.g., for securing elongate objects or a bunch of conduits such as pipes and the like.
From the state of the art, different embodiments of so-called rail nuts are known. E.g., German Publication DE 38 11 974 A1 discloses a spring-biased rail nut having longitudinal grooves in which the rim webs of a C-shaped rail engage in the pivotal position of the nut.
German Publication DE 196 35 632 A1 discloses a rail nut the transverse extension of which is inserted in a slot-shaped opening in a C-shaped profile rail, and the longitudinal extension of which is greater that the inner dimension of the slot-shaped opening so that upon rotation of the nut the nut engages from behind the rims of the slot-shaped opening.
German Patent DE 196 17 750 C1 also discloses a rail nut which is inserted in a mounting opening in a C-shape mounting rail and is the rotated. During a setting process of the nut, it is aligned for engagement from behind the longitudinal edges of the mounting opening by a release member.
German Publication DE 100 52 534A discloses an attachment element insertable in a mounting opening of a hollow body and having a rotatable engagement member for engaging from behind longitudinal edges or rims of the mounting opening. With this attachment element e.g., angles for connecting two mounting rails can be secured on the mounting rails.
The drawback of the known solutions consists in that the length of the contact surface of the engagement member is limited by the slot width of the mounting rail. Thereby, only a limited value of transverse forces can be absorbed by conventional attachment elements. With inclined or vertically extending conduit strands or with axially loaded conduit strands, and in devices for connecting two mounting rails, substantial transverse forces act on the attachment element.
Accordingly, an object of the present invention is to provide an attachment element that insures a reliable connection under action of significant transverse forces.
Another object of the present invention is to provide an attachment member that can be easily inserted in amounting opening of a hollow body at any arbitrary selected location along the longitudinal axis of the hollow body.